This book can be viewed as a response to a call sounded by Dr. Thomas Mahnken at the Forces Transformation Chairs Meeting in February 2007. Dr. Mahnken, Deputy Assistant Secretary of Defense for Policy Planning, pointed out that the United States responds to shocks most successfully when it has already recognized and responded to the trends from which they emerge. It is less successful when those trends have gone unidentified or when no effective response to them has been mounted. One case where the trends were not recognized in time was the terrorist attacks of September 11, 2001. It thus becomes necessary, Dr. Mahnken concluded, to develop a means of identifying trends and responding to them before acute challenges emerge. Forecasting International (FI) heartily agreed. FI is one of the world's premier futurist organizations. It specializes in the analysis of trends. To our knowledge, we were the first such organization to apply trend analysis to the problem of terrorism. We did so with considerable success. FI began its work on terrorism in 1994, when it managed the 4th Annual Defense Worldwide Combating Terrorism Conference for the Pentagon. Its conference report, Terror 2000: The Future Face of Terror, accurately predicted the rise of Muslim extremism as a source of terror, the terrorists' growing taste for mass bloodletting, the use of coordinated attacks on distant targets, and even an assault on the Pentagon using a hijacked airplane (omitted at the request of the State Department). Since then, FI has often studied terrorist issues for both government and private industry. In the current report, FI examines the future of international terrorism. In this effort, it has been assisted by more than fifty of the world's premier authorities in the fields of antiterrorism, intelligence, security, and policing. This expert panel included members of the intelligence community, specialists from the U.S. government and military, security consultants, think tank staffers, forecasters, university professors, and local police officials. Most came from the United States, but Australia, Canada, Ireland, New Zealand, Russia, and Switzerland also were represented. Several participants chose to remain anonymous, owing to their sensitive positions in government and the military. One contributor is a private citizen of whom we know nothing, save that he responded to a magazine article we had published and provided some interesting thoughts. This typifies our approach in this work. We have tried to be inclusive, rather than exclusive. FI's own views, and those of certain experts, dominate the report, but some have been included-often in the appendices-specifically because they diverge from the mainstream and might provide useful insights or novel ideas that would not arise from more conventional sources. We have tried to omit nothing that should at least be considered. Many of the ideas presented here deserve to be seen at the highest levels of government. Key findings from our panel of experts include: International terrorism will grow as veterans of the Iraq War return to their native lands, train sympathizers in the tactics of terror, and spread out across the world. Among the Western lands, Britain and France (owing to their large Muslim populations) and the United States will be at the greatest risk of attack, in that order. Further attacks on the scale of 9/11 are to be expected in all three countries over the range of five to ten years.